Color silver halide photographic materials rely on coupler compounds to form dyes that make up the image recorded in such materials. Usually a yellow dye-forming coupler will be associated with a blue-sensitive silver halide emulsion layer, a magenta dye-forming coupler will be associated with a green-sensitive silver halide emulsion layer, and a cyan dye-forming coupler will be associated with a red sensitive silver halide emulsion layer. These coupler compounds form image dyes by reaction with color developer compound (e.g., phenylene diamine) that has been oxidized by reaction with exposed silver halide.
One well known class of magenta dye forming couplers are pyrazoloazole couplers according to the general formula: ##STR2## wherein
R.sub.1 represents hydrogen or a substituent,
X represents hydrogen or a group capable of being released by a coupling reaction with an oxidized aromatic primary amine developing agent, and
Z represents the non-metallic atoms necessary to complete a heterocyclic ring.
It is often desirable adjust the reactivity of such couplers by attaching various ballast groups to the Z ring of the above described pyrazoloazole couplers. One such coupler has the formula: ##STR3##
It is also often desirable to attach pyrazoloazole couplers to polymeric chains. This can provide a variety of advantages, such as reduced wandering, reduced crystallinity, and thinner layers. However, when couplers such as C-1 above are attached to a polymeric chain, as with a polymerized version of the monomer shown below: ##STR4## the polymeric coupler exhibits a high level of inhibition of silver development. This reduces the effective speed of the silver halide emulsion. Also, many polymeric couplers, such as C-2, are still subject to wandering.
It is therefore desirable to provide a polymeric pyrazoloazole coupler that has the desired reactivity, and does not suffer from undue inhibition of silver development.